Senior Backend Developer – Services

payabl.

Senior Python Backend Developer designing scalable microservices and transforming legacy systems. Collaborating with teams to ensure high reliability and maintainability in backend architecture.

Posted 6/22/2026full-timeRemote • 🇵🇱 PolandSeniorWebsite

ATS Keywords

Tailor your resume

Applicant Tracking System Keywords

Tip: use these terms in your resume and cover letter to boost ATS matches.

Hard Skills

PythonAsyncIOFastAPIMySQLPostgreSQLunit testingintegration testingwebhookscallbacksmicroservices

Soft Skills

ownership mindsetconfidence in complex systemscuriosity for productstrong English communicationproduct thinkingagile collaborationinnovation

Tools & Technologies

DockerKubernetesCI/CDKafkaRedis

Industry Keywords

fintechpayments3DSToken Management Systemspayment gateway integrations

Tech Stack

Tools & technologies

DockerGoJavaScriptKafkaKubernetesMicroservicesMySQLPerlPHPPostgresPythonRedis

About the role

Key responsibilities & impact

Legacy Modernisation: Read legacy code (PHP, Perl, or JavaScript), extract the business logic, and reimplement it correctly within a modern microservices architecture.
Reliability First: Ensure idempotency, data integrity, and graceful error handling across all services — "almost working" is never good enough.
Greenfield & Refactoring: Split your time between building new features from scratch and refactoring existing legacy modules into clean, maintainable code.
API Engineering: Design and consume external APIs with a deep understanding of webhooks, callbacks, and complex retry policies.
Agile Collaboration: Maintain clean and strong English communication to effectively collaborate with multiple stakeholders across departments working in agile sprints.
Product Thinking: Go beyond the "what" and "how" of the code — bring a product-focused mindset to understand the business logic and end-user impact of what you build.
Infrastructure Contribution: Contribute to CI/CD pipelines, Docker, or Kubernetes infrastructure where relevant. If you have a passion for infra, you are more than welcome to bring it.
Innovation: Propose and advocate for tools or technologies that can demonstrably improve our performance, security, or development speed.

Requirements

What you’ll need

Python Mastery: 5+ years of backend engineering experience with strong Python expertise. Deep AsyncIO proficiency — you must be comfortable building non-blocking, high-reliability microservices.
Framework Expertise: Production-grade experience with FastAPI (not just familiarity).
Databases: Experience with MySQL and/or PostgreSQL — query design, schema understanding, and migration strategies.
Testing Discipline: Experience writing unit and integration tests (pytest preferred).
API & Reliability Patterns: Expertise in designing and consuming external APIs with a deep understanding of webhooks, callbacks, and complex retry policies.
Ownership Mindset: Willingness to take full ownership of high-traffic, always-up applications and operate independently within an established architectural vision.
Confidence in Complex Systems: Comfortable in complex distributed environments where reliability is non-negotiable.
Clean & Intentional Code: We value deep engineering logic over AI-generated snippets. You must be able to explain the reasoning behind every line you ship.
Curiosity for Product: You care about the "why" behind a feature — how it works for the end-user and what it means for the business.
Strong English: Both written and verbal to collaborate effectively across multi-functional teams.
Nice to Have: Experience with PHP, Perl, or JavaScript — a strong bonus signal for legacy comprehension.
Kafka / Redis experience.
Docker / CI/CD / Kubernetes familiarity.
Financial industry exposure — fintech, payments, 3DS, Token Management Systems, or payment gateway integrations.
Track record of successfully migrating systems from one language or paradigm to another.

Benefits

Comp & perks

Grow with Us: Annual Learning Budget for professional development (eligible after probation)—because your growth is our growth.
Celebrate Together: We bring colleagues from all offices together for unforgettable company celebrations.
Global Collaboration & Events: Opportunities to participate in international company events and initiatives, connecting with colleagues from all regions and contributing to a truly global community